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Semiconductor manufacturing is performed through unit processes that use various chemicals and facilities. In particular, flammable gases, such as H2, NH3, and CH4, are used, and there is a risk of explosion when such gases leak. In this study, computational fluid dynamics (CFD) simulation and a "tracer gas test" according to the SEMI (Semiconductor Equipment and Materials International) S6 Environmental, Health, and Safety Guideline for Exhaust Ventilation of Semiconductor Manufacturing Equipment specification were performed during the leakage of hydrogen, a highly flammable gas used in the etching process of a gas box in the semiconductor industry. The CFD simulation was conducted to investigate the safety of semiconductor production facilities in relation to the explosion risk. Flow analysis was performed for the interior of a gas box used in the etching process. A steady-state analysis was performed to predict the concentration range of the explosion limit in the case of continuous hydrogen gas leakage. The interior of the gas box used in the simulation was modeled, and the ventilation flow rate, which has a significant impact on the leakage gas concentration distribution, obtained from experiments was used. The lower flammability limit (LFL) value of the leaked gas was 4% based on H2, and LFL/4 (25% of the LFL) was analyzed as the explosion limit concentration according to the acceptance criteria of the SEMI S6 tracer gas test. To validate the CFD simulation, a tracer gas test was performed according to SEMI S6. A mixture of hydrogen (5%) and nitrogen (95%) was used as the tracer gas. The flow rate was controlled by a gas regulator valve and measured using an Aalborg mass flow meter. The measured concentration of the tracer gas was calculated using the equivalent release concentration, which was calculated when 100% of the hydrogen was released, and the risk was assessed by comparing it with the LFL/4 of H2. [ABSTRACT FROM AUTHOR]

In the semiconductor industry, hydrogen is used with many other hazardous and dangerous substances with flammable, toxic, and corrosive properties. In order to safely handle them, convenient-to-use gas cabinets are often required. As known well, hydrogen is highly flammable and explosive, and risk analysis needs to safely use the gas in the cabinets. In this study, overpressure and impact according to various gas cabinet conditions were measured when hydrogen leaks in the gas cabinet, and the effect of overpressure on the protective wall was simulated. For the research, a demonstration experiment was conducted by custom manufacturing a gas cylinder cabinet identical to the standard used in the field, and the protection performance analysis was performed by reverse-engineering it through 3D scanning. As a result of the demonstration experiment, the maximum pressure at the time of hydrogen gas explosion in the gas cylinder cabinet was measured at 0.3 bar. After calculating the detonation pressure propagation profile using the TNT equivalence method, the protective performance of the protective wall was confirmed using AUTODYN. The maximum stress of the concrete and the maximum stress of the reinforcing bar due to the explosion in the gas cylinder cabinet were calculated to be 30.211 MPa and 112.88 MPa, respectively, which do not exceed the tensile strength of concrete and the yield strength of the reinforcing bar. This result is expected to be of great help to the development of the semiconductor industry by suggesting the rationale for mitigating the firewall when changing the semiconductor layout. [ABSTRACT FROM AUTHOR]

The building sector is one of the largest contributors to the world's total energy use and greenhouse gas emissions. Advancements in building energy technologies have played a critical role in enhancing the energy sustainability of the built environment. Extensive research and new techniques in energy and environmental systems for buildings have recently emerged to address the global challenges. This study reviews existing articles in the literature, mostly since 2000, to explore technological advancement in building energy and environmental systems that can be applied to smart homes and buildings. This review study focuses on an overview of the design and implementation of energy-related smart building technologies, including energy management systems, renewable energy applications, and current advanced smart technologies for optimal function and energy-efficient performance. To review the advancement in building energy-related technologies, a systematic review process is adopted based on available published reviews and research types of articles. Review-type articles are first assessed to explore the current literature on the relevant keywords and to capture major research scopes. Research-type papers are then examined to investigate associated keywords and work scopes, including objectives, focuses, limitations, and future needs. Throughout the comprehensive literature review, this study identifies various techniques of smart home/building applications that have provided detailed solutions or guidelines in different applications to enhance the quality of people's daily activities and the sustainability of the built environmental system. This paper shows trends in human activities and technology advancements in digital solutions with energy management systems and practical designs. Understanding the overall energy flow between a building and its environmentally connected systems is also important for future buildings and community levels. This paper assists in understanding the pathway toward future smart homes/buildings and their technologies for researchers in related research fields. [ABSTRACT FROM AUTHOR]